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Reieeued Jan. 31,- 1928.'

"UNITED STATES PATENT OFFICE.

RUSSELL B. CBO'WELL, P AGNEW, AND GERALD I. BRECKENRIDGE, 01' SAN JOSE,CALIFORNIA. ASSIGNORS, BY MESH-ASSIGNMENTS, '10 AMERICAN SOLVENTB QCHEMICAL CORPORATION OF CALIFORNIA, A CORPORATION OP DELAWARE.

PROCESS FOR PRODUCING ALKALI-IE'IAL ZANTHATES.

I o Drawing. Original No. 1,558,504, dated October '27, 1825, serial No.81,808, nled Kay 18, 1885.

Application for reissue filed December 82, 1827. Serial No. 248,001. I

This invention relates-to processes at roducing salts of :xanthic orethyloxydit 1ocarbonieacid of the alkali metals such as sodium orpotassium.

5 It has been proposed. to produce the alkali metal xanthates such assodium or potassium xanthates by causing a reaction'to take filacebetween a hydroxideof the alkali meta such as sodium or potassium,carbon bisulphide, and ethyl alcohol, the reaction being carried outeither in the presence of an aqueous mediumor in the presence of anexcess of alcohol. In processeswherem this reaction is carried out in anaqueous medium the water has the efiect of mate- 4 riall reducing theercentage yield of the xant ate salts there y causing an increase in thecost thereof. Processes in which the reaction takes place in thepresence of an excess of alcohol present the disadvantage that thealcohol utilized in the process is either lost or is recovered only withgreat difiiculty therefrom, thereby causing such processes to benecessarily costly. Another well known'process of producing sodiumxanthate is that in which the metal sodium is dissolved in dry alcohol,and to this solution is added a calculated quantity of dry carbonbisulphide, the reacting mixture be-- ing continuously cooled andagitated until the reaction-is complete. Accordingly, one of the objectsof this invention is to rovide an improved process of producin al alimetal xanthates wherein a mixture 0 a hydroxide of an alkali metal.carbon bisulphide, and alcohol are reacted in the absence of either anaqueous medium "or an excess of alcohol.

' Another object of this invention is to pro- Yide an improved method'ofproducing the salts of xanthic acid of the alkali-metals which resultsin a high percentage yield of such salts in-a substantially purer stateand at lower cost than is the case in the processes of the prior art.

Other and further objects of this invention will appear from the moredetailed description of this invention set forth here'- inafter, itbeing understood thatvarious changes may be made therein by thoseskilled in the art without departing fromthe scope and spirit -'of thisinvention as defined in the appended claims.

In one preferred embodiment of carrying out our invention we take eitheranhy'drous sodium or potassium hydroxide,

vthe choice of the hydroxide being dependent upon which one of theparticular xanthate saltsof the alkali metals, is desired, in amountsequivalent to their molecular Weights and grind or reduce the same to agranular or powdered state with the particles of such size that thecrushed material will pass through a screen of 80 mesh or greater. Thispulverulent anhydrous material is then admixed with a hydrocarbon liquidbody as kerosene, gasolene, toluene, or a similar liquid which possessesthe inherent property of being chemically inert to such hydroxides,under vigorous agitation. As soon as the hydroxide is thoroughmixturecontaining the suspensoid, the reacting mass is cooled andsimultaneously subjected to vigorous agitation, such agitation andcooling being continued until the reaction is complete. The xanthatesalt,

either the sodium or potassium xanthate de pendent upon the specifichydroxide comgradually pound-utilized in the process appears as a.

yellow precipitate, and can be readily recovered fromthe mass. a

The procedure outlined above ma be varied. in that the finely groundanhydrous hydroxide of sodium or potassium in an amount e uivalent toits molecular weight may be a 'ded to the kerosene, gasolene or similarliquids, the mixture then-vigorously stirred until a suspensoid of thehydroxide in a-liquid non-aqueous medium is produced, and then addingto-the suspensoid mass a mixture consisting of alcohol and carbonbisulphide in amounts equivalent to their molecular weights, the wholemass being vigorously a itated and cooled during the reaction. T edproceduremay be further modified by ad ing part of the requisite amountof alcohol 0 the hydroxide suspensoid mixture, and a part of the alcoholto the requisite amount of carbon bisulphide, and then bringing the twoportions tother under v1 orous a itation in a vessel g g cooling meansprovided with suitable through which an appropriate cooling medium iscaused to circulate, durin the interval in which the mass reacts an thereaction is completed.

The percentage ield of the xanthate salts of the alkali meta s as sodiumor potassium roduced by the rocesses hereinabove set orth is high, ansuch salts are in a substantially pure state. The xanthate salts may bereadily recovered from thereacted mass and ma be dried in the usualmanner or if desire for immediate use maybe dissolved in water.

Having described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. The process of producing alkali metal xanthates which comprisesreacting a sus.-

endedhydroxide of an alkali-metal, alcool, and'carbon bisulphide in aliquid hydrocarbon medium chemically inert to the remaining ingredients.

2. The process of producing alkali-metal xanthates which comprisesreacting a mixture of a suspended hydroxide of an alkalimetal alcohol,and carbon bisulphide, in a liquid hydrocarbon medium chemicall inerttov the remainin ingredients, said mixture being subjecte to agitationand being cooled during the reaction.

3. In the process of producing alkali-met: a1 xanthates the steps whichcomprise forming a sus ension of an anh drous' alkali metal hy roxide ina liqui medium chemicall inert to said hydroxide, and adding alcohothereto.

4. In he process of producing alkaliaddition of the mixture of alcoholan hydrocarbon metal xanthates the steps which comprise forming a.suspension of an alkali-metal hydroxide in a liquid hydrocarbon mediumchemically inert to said hydroxide and adding alcohol and carbonbisulphide thereto.

5. In the process of producing alkalimetal xanthates the steps whichcomprise forming a suspension of anhydrous alkalimetal hydroxide inaliquid hydrocarbon medium chemically inert -to the said hyadding carbonbisulphide.

6. The process of producing alkali metal xanthates which comprisesformin a suspension of an alkali metal hydroxide in a liquid hydrocarbonchemically inert to said hydroxide, adding alcohol thereto, and thenadding a mixture of alcohol and carbon bisulphide tothealcohol hydroxidemixture.

7. The process asset forth in claim 6 .droxide, adding alcohol thereto,and then wherein the hydroxide suspension is subjected to agitationduring the addition of the alcohol thereto.

'8. The process as set forth in claim 6' wherein the alcohol hydroxidemixture isthe car-

cooled and vigorously agitated durin bon bisulphidethereto. I

9. The process of producing alkali metal xanthates which comprisesforming a suspension of an alkali metal hydroxide in a liquidhydrocarbon chemically inert to said hydroxide, adding alcohol thereto,cooling the mixture, adding carbon bisulphide, and recovering the saltthus produced.

10. The process of producing alkali metal xanthates which consists informing a suspension of an alkali metal hydroxide in a liquidhydrocarbon chemically in ert to said hydroxide, adding alcohol thereto,cooling the mixture, adding an admixture of alcohol and carbonhisulphide to said mixture, and recovering the salts thus produced.

' In testimony whereof we afiix our signatures.

RUSSELL B. CROWELL. GERALD F. BRECKENRIDGE.

